1. Field of the Invention
This invention relates to method for making light assemblies typically used to mount panes of glass in metal doors, interior and exterior walls or partitions and particularly to means for embossing an indented edge around the opening used to mount a glass pane and surrounding frames in the panel light aperture.
2. Description of Related Art
Light assemblies used to mount glass panes in the apertures of doors, walls, partitions, and similar structures conventionally include a glass pane, typically being of the single or double glazed type, and mounted in a light aperture of the panel between two frames, often referred to as trim. The frames are used to trap the pane between them and are held in place against the outer surfaces of the panel by a clamping assembly that uses cylindrical fasteners such as bolts, rivets, or the like. In the case of U.S. Pat. No. 3,903,669 a rather complicated and expensive double male ended stud is received in bores in the plastic frames which lacks strength and durability. These fasteners require significant assembly time which increases the cost of construction.
Conventional light assemblies and in particular ones used for metal fire doors have frames that protrude outward from the door's outer surfaces and interfere with door hardware that is mounted thereupon. Such hardware includes but is not limited to a flat bar panic device which is mounted transversely across the door and for which it may not be possible, desirable, or safe to place elsewhere particularly in light of handicap related building and housing codes.
A panel light assembly was developed that is flush mounted to the door's outer surfaces so that the frames do not protrude above the outer surfaces and interfere with the mounting of hardware such as a transversely mounted bar like panic device. This panel light assembly and door is the subject of a related patent application Ser. No. 07/991,138 entitled "Door Window Glass and Frame Assembly", by Robert O. Ruff, filed Dec. 16, 1992 and assigned to the same assignee. A feature of panel and more particularly a door is embossed indented edges along the periphery of the light aperture for mounting the light's pane and frame assembly therein.
The door and other panels are conventionally formed from a single blank of sheet metal. The panels are typically formed using conventional sheet metal forming tools in an assembly process that is often highly automated in order to make precise cuts, bends, and folds to insure good fits. Forming the light aperture and its embossed edges poses a serious problem for both the aperture forming steps and the remainder of the panel forming process. The light aperture could not be cut out from the flat blank and the embossed edges formed prior to bending the panel into the final door shape because the aperture would reduce the stability of the panel to a point where it could not easily be processed by conventional machinery in an economical manner. Therefore, a need exists for a method to form the panel and the light aperture with embossed edges before the blank is bent and formed into its final shape and also so that the panel will not have its stability significantly reduced so as to degrade its ability to be formed into a panel. The present invention was developed to provide such a method and to do so in an accurate and efficient manner.